This study assessed the associations of maternal attachment classification with mother and daughter depression and affect regulation, with the hypothesis that affect regulation might mediate between attachment and depression both within and between generations. Twenty-five dysthymic mothers, 25 non-depressed mothers, and their adolescent daughters, ages 15 to 20 recruited from Ann Arbor, Michigan, and surrounding communities were interviewed using the Adult Attachment Interview. Self-report measures of depression (Center for Epidemiological Studies-Depression Scale) and affect regulation (Affect Regulation Scale) were also administered. Results indicated that most dysthymic mothers were insecure, and most depressed daughters had insecure mothers. A moderate curvilinear relationship was found between mothers' and daughters' depression. Dysthymic mothers used fewer adaptive affect regulation strategies than non-depressed mothers. Depression in both mothers and daughters was correlated with high use of maladaptive strategies and with a lower tendency to use successful strategies more often than unsuccessful strategies. There was no association between affect regulation and attachment, even though depression was associated with both attachment and affect regulation. Results suggested that maternal insecurity may be a stronger influence than actual symptoms of depression on daughter depression, both independent of and in interaction with the mother's own depression. The proposed mediating role of adaptive versus maladaptive affect regulation was not supported; however, other dimensions of affect regulation, such as defense mechanisms, may perform this mediating role. (Contains eight references and nine tables.) (Author/KDFB)